Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 cee58f328a1e2f2a…

MALICIOUS

RTF / .DOC

24.2 KB First seen: 2022-11-30
MD5: 060e8c7defc53d9c8bc91b6b6df48ccb SHA-1: f45fec379e505e812daff93b3523e09fe54c75df SHA-256: cee58f328a1e2f2ad586e8ddf0dd5df0e99b149f34ee9cda05666c59047852c9
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File

The sample is an RTF document containing an embedded OLE object, specifically targeting the Equation Editor vulnerability. The presence of \objupdate indicates an attempt to automatically activate the object upon opening. The document body contains a lure to 'Enable editing', a common tactic to bypass macro security and trigger the exploit. The heuristics strongly suggest exploitation of the Equation Editor via an embedded OLE object.

Heuristics 4

  • Split hex Equation Editor ProgID + OLE object critical RTF_EQUATION_EDITOR
    RTF embeds the Equation.3 ProgID as hex bytes near OLE object activation and splits the byte stream with whitespace or an ignorable RTF group. This is an Equation Editor OLE activation surface commonly used by CVE-2017-11882 / CVE-2018-0802 exploit documents.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 1 \objdata section(s) — embedded OLE objects
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off0000462f.bin
2cb632114ec094ee018d589fa56fc7f6c694c2cacb1bb505c39c6a74ba278df5
rtf-objdata-decoded RTF \objdata at offset 0x462F 1958 bytes